University  of  California— College  of  Agriculture, 

AGRICULTURAL  EXPERIMENT  STATION. 

E.  W.  HILGARD,  Director. 


REPORT  ON  CONDITION  OF  VINEYARDS  IN  PORTIONS 
OF  SANTA  CLARA  VALLEY. 


By  FREDERIC  T.  BIOLETTI  and  E.  H.  TWIGHT. 


DECAYED  TRUNK 


(See  page  4.) 


SOUND  TRUNK. 


BULLETIN    No.    134. 

(Berkeley,  Sept.  23,  1901.) 


SACRAMENTO: 
a.  j.  Johnston,  :::::::  superintendent  state  printing. 

1901. 


Digitized  by  the  Internet  Archive 

in  2012  with  funding  from 

University  of  California,  Davis  Libraries 


http://www.archive.org/details/reportonconditio134biol 


UNIVERSITY  OF  CALIFORNIA, 

AGRICULTURAL  EXPERIMENT  STATION. 
COLLEGE   OF    AGRICULTURE, 

E.  W.  Hilgard,  Director. 
Berkeley.  California. 


August  26,  1901. 
Professor  E.  W.  Hilgard, 

Director  of  Agricultural  Experiment  Station. 
Dear  Sir:  In  accordance  with  your  directions  we  have  examined  the 
vineyards  of  Santa  Clara  with  the  object  of  determining  the  cause  of 
the  failure  and  death  of  a  large  number  of  vines  in  parts  of  that  county 
during  the  last  three  years.  It  is  not  possible  at  present  to  give  a  com- 
pletely satisfactory  explanation  for  such  serious  and  widespread  damage 
as  has  occurred,  but  our  observations  seem  to  prove  conclusively  two 
propositions:  First,  that  the  dying  vines  exhibit  symptoms  differing 
materially  from  those  shown  by  the  vines  in  Southern  California  which 
were  destroyed  by  the  Anaheim  disease;  and,  second,  that  whether  or 
not  there  be  some  "  unknown  influence  "  at  work,  as  suggested  by  Mr. 
Newton  B.  Pierce,  the  real,  determining  factor  is  the  deficiency  of  rain- 
fall during  the  years  1897-1900. 


Area  and  General  Character. — The  dying  of  vines  without  perceptible 
adequate  cause  during  the  last  three  years  has  by  no  means  been  con- 
fined to  the  west  side  of  the  Santa  Clara  Valley.  Similar  cases  have 
been  reported  and  investigated  over  a  wide  area  extending  from  the 
northern  part  of  Sonoma  County,  to  the  western  and  southern  parts  of 
the  Santa  Clara  Valley,  and  including  nearly  all  the  older  vineyard 
districts  within  these  limits.  The  only  peculiarity  of  the  cases  on  the 
west  side  of  the  Santa  Clara  Valley  is  their  number,  extending  in  many 
cases  to  every  vine  in  a  vineyard.  The  distribution  of  the  injured  and 
dead  vines  is  not  in  any  of  the  cases  examined  such  as  to  suggest  an 
infectious  parasitic  cause.  In  some  instances  single  vines  failed  and 
died  sporadically  where  the  main  bulk  of  the  vineyard  was  in  fair  con- 
dition, and  a  dead  vine  was  usually  surrounded  by  vines  which  were 
apparently  healthy. 

Nature  of  Injury. — In  most  of  these  sporadic  cases  examined  the  dying 
vine  was  found  to  have  been  severely  injured  in  some  way,  usually  by 
cutting  off  large  branches  at  the  pruning  and  thus  causing  large  wounds. 
Vines  of  this  kind  when  split  open  were  found  to  be  more  or  less 
decayed  in  the  middle,  and  many  were  quite  hollow.  In  a  report  made 
to  you  last  year  on  the  same  subject  this  decay  of  the  interior  of  the 
trunk  was  suggested  as  the  cause  of  death  in  some  cases.  This  year, 
however,  though  in  some  vineyards  the  hollow  vines  have  continued  to 


__  4  — 

fail  and  die,  in  others  they  have  recovered.  This  indicates  that  though 
the  wood  decay  may  have  contributed  to  the  effect,  it  is  not  the  only, 
nor  indeed  the  chief  cause. 

The  accompanying  photograph  (plate  1)  illustrates  the  injury  done 
by  the  cutting  off  of  a  large  branch. 

Note  in  the  subjoined  figure  the  large  wound  which  could  not  heal 
over,  and  which  allowed  a  large  amount  of  wood  to  dry  out.     Note  also 


PLATE  1. 


Vine  Injured  by  Heavy  Pruning  Without 
Protection  to  Wound. 


the  hole  made  by  a  boring  insect,  which  allowed  the  entrance  of  moisture 
and  of  white  ants,  and  thus  favored  the  growth  of  wood-rot  fungi.  The 
stem  of  this  vine  was  found,  on  being  split,  to  be  quite  hollow  nearly 
down  to  the  surface  of  the  ground.  For  the  general  appearance  of  vines 
of  this  kind  see  the  frontispiece,  which  is  taken  from  a  photograph  of 
one  of  the  vines  as  it  appeared  in  1900.  Note  the  contrast  with  the 
perfectly  healthy  appearance  of  the  neighboring  vine. 

Nature  of  Soil. — Nearly,  if  not  quite,  all  the  cases  occurred  in  grav- 
elly soil,  and  the  more  gravelly  the  soil  the  more  numerous  and  serious 


—  5  — 

the  cases.  Soil-borings  in  the  most  badly  affected  vineyards  showed  a 
layer  of  many  feet  of  coarse  gravel,  commencing  at  two  or  three  feet 
from  the  surface.  In  attempting  to  irrigate  in  these  places  the  growers 
had  much  difficulty  in  causing  the  water  to  flow  to  all  parts  of  the  vine- 
yard. A  large  stream  of  water  would  take  many  hours  in  passing  a 
few  yards,  on  account  of  the  extremely  leachy  nature  of  the  soil,  which 
allowed  the  water  to  escape  downward. 

Age  of  Vines. — It  is  to  be  noted  that  none  of  the  dying  vines  are 
young.  All  the  vineyards  examined  which  were  less  than  eight  years 
old  showed  no  indications  of  failing  or  dying.     All  cases  of  young  vines 


PLATE  2.    Two  Healthy  Trousseau  Vines  in  a  Vineyard  of  Dead  Mataro  Vines. 

failing  which  were  examined  were  plainly  due  to  lack  of  cultivation, 
phylloxera,  sunburn,  or  other  well-known  and  adequate  causes. 

Another  fact  worth  mentioning  in  this  connection  is  that  old  vines 
which  were  grafted  just  before  the  three  dry  years,  are  now  nearly  or 
quite  healthy.  In  one  vineyard  a  block  of  old  Mataro  grafted  with 
Verdal  about  1896  shows  strong  growth  and  no  signs  of  failing,  while  a 
contiguous  block  of  the  same  variety  and  age,  but  un grafted,  is  prac- 
tically dead. 

Behavior  of  Different  Varieties. — A  great  deal  of  difference  was  every- 
where noted  in  the  behavior  of  different  varieties  of  vines.  The  most 
seriously   affected    were    Mataro,    Zinfandel,   Rose   of    Peru,   Mission, 

Varieties  less  affected  were  Grenache,  Muscat, 


Emperor,  and  Burger. 


and  Verdal.  These  three  varieties,  in  many  cases  where  they  looked 
very  bad  last  year  and  even  this  spring,  appear  to  be  recovering. 
Other  varieties  show  little  or  no  damage.  The  chief  of  these  noticed 
were  Trousseau,  Cabernet-Sauvignon,  Pinot  (?),  Verdot,  Robin  noir,  and 
Herbemont.  This  list  indicates  that  the  heaviest  bearers  are  the  most 
seriously  affected  and  that  all  the  immune  varieties  are  light  bearers. 
This  difference  in  varieties  was  so  marked  that  several  Trousseau  vines 
growing  in  a  Mataro  block  were  apparently  perfectly  healthy  and 
vigorous,  while  the  Mataro  were  all  dead.  This  is  shown  in  the  photo- 
graph (plate  2).  The  recovery  of  less  susceptible  varieties,  such  as 
Grenache,  was  in  several  cases  very  remarkable.  Two  adjacent  blocks, 
one  of  Grenache  and  the  other  of  Mataro,  showed  a  remarkable  contrast 


PLATE  3.    Adjacent  Blocks  of  Mataro  (Dead)  and  Grenache  (Recovering). 

when  examined  in  August  of  this  year.  Both  blocks  had  made  very 
short  growth  in  1900,  but  this  year  all  the  Mataro  were  dead,  while 
none,  so  far  as  could  be  seen,  of  the  Grenache  had  died,  and  though  the 
block  had  looked  sickly  in  the  spring,  when  examined  in  August  it 
showed  a  fine  growth  of  luxuriant  foliage  (see  plate  3). 

To  recapitulate;  the  main  facts  ascertained  are: 

1.  All  the  dying  vines  are  old. 

2.  All  the  serious  cases  are  in  gravelly  soil. 

3.  The  varieties  most  injured  are  all  heavy  bearers. 

4.  Vines  grafted  before  the  drought  are  healthy. 

5.  Vines  showing  serious  mechanical  injuries  succumb  first. 

6.  Vines  which  have  not  become  too  weak  appear  now  to  be  recov- 
ering. 


Causes. — These  facts  seem  to  indicate  that  we  can  ascribe  the  failure 
of  the  vines  to  a  general  cause  acting  over  the  whole  district;  a  cause, 
however,  which  was  only  effective  where  supplemented  by  one  or  more 
contributory  conditions.     These  conditions  are: 

1.  Excessively  gravelly  soil. 

2.  Susceptibility  of  the  variety  of  vine,  due  probably  to  heavy  bearing 
and  perhaps  to  some  peculiarity  of  wood  and  foliage,  or  roots. 

3.  Large  wounds  made  in  pruning. 

4.  Age  of  the  vine. 

5.  Severe  cutting  back  of  the  young  growth  by  spring  frosts. 

The  general  cause  seems  to  be  the  combined  effect  of  the  heavy  crops  of 
1896  and  1897  and  the  four  years  of  drought  which  followed. 

Rainfall  and  Crops. — The  following  statistical  table,  made  up  from 
data  furnished  by  the  Weather  Bureau  and  by  two  of  the  largest  vine- 
growers  in  the  most  seriously  affected  districts,  fortifies  the  above 
position : 

Relation  of  Precipitation  and  Irrigation  to  Crop,  in  Vineyards  in  Santa   Clara  Valley. 


Precipitation 
at  Santa  Clara. 

Crop  on  Vineyards  at  West  Side. 

Departure 

from  Normal 

Rainfall. 

A  (300  acres). 

B  (170  acres). 

1896             

Inches. 
19.51 

11.82 

8.13 

15.56 

13.15 

Tons. 
1,413 

1,883 

500 

a  449 

6315 

Tons. 

dSOO 
d2l5 
d  93 
c    94 

Inches. 
+3.24 

—4.45 

—8.14 

1897 

1898 

1899 

1900 .- 

—  .71 
-3.12 

a  Irrigated  35  acres. 

b  Irrigated  300  acres. 

c  Irrigated  70  acres  in  February.  From  50  acres  of  the  irrigated  land  were  obtained 
49  tons  of  grapes,  and  from  the  remainder  of  the  vineyard  only  45  tons.  This  indicates 
about  1  ton  per  acre  on  the  irrigated  and  about  %  ton  per  acre  on  the  unirrigated 
portion. 

d  Estimated  from  the  wine  produced. 


If  the  figures  given  for  these  two  vineyards  are  typical,  which  there 
is  every  reason  to  suppose,  they  may  help  us  to  find  a  sufficient  cause 
for  the  death  of  the  vines  without  taking  refuge  behind  the  mysterious 
and  highly  unsatisfactory  Anaheim  disease.  In  1896  the  vines  bore  a 
large  crop,  but  were  supplied  with  sufficient  water  by  a  rainfall  of  three 
inches  above  the  normal.  They  therefore  entered  the  season  of  1897 
healthy,  but  probably  not  with  an  excess  of  reserve  food-material  laid 
up  in  the  stems  and  roots;   for  the  weakening  effect  which  a  heavy  crop 


—  8  — 

often  has  upon  a  plant  is  due  to  the  fact  that  the  nutriment  which  it 
absorbs  and  assimilates  during  the  summer  and  autumn  is  nearly  all 
utilized  in  the  production  of  fruit,  and  little  is  stored  for  use  in  the  fol- 
lowing spring.  The  spring  growth  of  a  plant  is  all  due  to  this  reserve 
food,  and  is  the  weaker  the  less  of  this  reserve  it  has  to  draw  upon. 
Usually  a  year  of  heavy  bearing  is  followed  by  a  year  of  light  bearing, 
during  which  the  plant  is  able  to  recuperate  by  utilizing  the  food 
assimilated  during  that  year  for  building  up  its  vegetative  organs  and 
for  replenishing  its  depleted  reserve.  During  the  season  following  the 
heavy  crop  of  1896,  however,  the  weather  conditions  were  evidently  such 
as  to  force  the  vines  to  expend  all  their  resources  in  the  production  of 
the  phenomenally  large  crop  of  1897.  How  exceptionally  large  this 
crop  was  upon  the  vines  which  are  now  dying  is  not  quite  indicated  by 
the  table  above,  which  includes  the  crop  from  all  varieties  and  ages  of 
vines.  The  crop  on  the  old  vines  of  heavy-bearing  varieties  which  are 
now  dead  was  doubtless  much  in  excess  of  the  indicated  average.  At 
the  same  time  that  this  severe  drain  was  being  made  upon  them  there 
was  a  shortage  of  over  four  inches  in  the  annual  rainfall.  It  is  practi- 
cally certain,  therefore,  that  these  vines  were  obliged  to  start  the  year 
1898  with  empty  storehouses,  and  the  rainfall  of  that  year  being  just 
half  the  normal,  the  vines  not  only  bore  very  little,  but  were  unable  to 
obtain  nutriment  sufficient  to  satisfy  their  vegetative  needs  and  to  nour- 
ish their  permanent  organs — roots,  stems,  and  canes. 

The  next  year,  1899,  therefore,  they  commenced  to  fail  and  some  of 
them  to  die.  In  1900  still  more  died,  while  in  1901,  the  present  year, 
the  largest  mortality  of  all  occurred.  It  is,  perhaps,  not  quite  clear 
why  the  mortality  should  be  greatest  in  the  later  years  when  the  defi- 
ciency of  rain  was  less  than  in  1898,  the  year  of  the  greatest  drought. 
It  should  be  remembered,  however,  that  a  lack  of  water  may  affect  a 
plant  in  two  ways:  If  it  occurs  at  a  time  when  the  plant  is  in  vigorous 
growth  and  full  leaf  the  plant  is  injured  or  killed  by  diminution  of  the 
amount  of  water  in  its  cells  and  tissues,  due  to  the  excess  of  evaporation 
from  the  leaves  over  the  absorption  by  the  root  hairs.  In  this  case  the 
plant  dies  of  thirst  and  dies  suddenly  at  the  time  of  the  drought.  If 
there  is,  on  the  contrary,  a  chronic  deficiency  of  water  in  the  soil,  com- 
mencing in  the  winter  before  the  plant  commences  to  grow,  the  result 
is  simply  a  small,  weak  growth  of  foliage,  insufficient  to  supply  food  for 
the  needs  of  the  stem  and  roots.  The  roots  thus  having  a  restricted 
food-supply  fail  to  grow  with  normal  vigor  and  in  turn  fail  to  supply 
the  rest  of  the  plant  with  the  soil  nutrients  which  it  is  their  function  to 
collect.  We  have  in  this  latter  case  not  so  much  injury  from  thirst  as 
gradual  starvation,  which  is  slower  in  its  action  and  probably,  when 
several  dry  seasons  follow  each  other,  cumulative,  as  the  reserve  food- 
supply  becomes  each  year  more  depleted  until  the  plant  dies. 


—  9  — 

Summary. — This,  then,  seems  to  us  the  true  explanation  of  the  death 
of  vines  in  the  Santa  Clara  Valley,  stated  in  a  few  words:  Slow  starva- 
tion, due  to  excessive  prolonged  drought  following  two  exceptionally  heavy 
crops.  That  some  vines  have  died  and  others  have  lived  is  due,  as  we 
have  shown,  to  cooperating  influences,  the  principal  of  which  are  the 
character  of  the  soil,  the  variety  of  grape,  the  age  of  the  vines,  and  the 
exhausting  effect  of  late  spring  frosts  in  certain  vineyards. 

The  objection  to  the  drought  theory  which  has  been  made,  that  irri- 
gated vines  have  suffered  as  much  as  unirrigated,  does  not  appear  to  be 
valid,  as,  in  all  the  cases  which  we  could  find,  the  irrigation  was  applied 
too  late.  Very  little  irrigation  was  practiced  until  1899,  and  then  only 
upon  the  worst  vineyards  where  the  vines  were  already  injured  beyond 
redemption.  The  irrigation  to  have  been  effective,  should  have  been 
given  during  the  winter  of  1897-98,  the  season  of  greatest  drought,  and 
immediately  succeeding  the  two  years  of  abnormally  heavy  crops. 
This  would  have  insured  the  strong  growth  of  foliage  during  the  fol- 
lowing summer  needed  to  repair  the  drain  of  the  preceding  years  and 
to  replenish  the  depleted  stores  of  reserve  food-supply  in  the  trunk  and 
branches.  That  irrigation  was  of  some  value,  even  when  practiced 
late,  is  indicated  by  the  record  of  vineyard  B  in  the  foregoing  table, 
which  shows  that  the  irrigated  portion  of  the  vineyard  produced  four 
times  the  crop  per  acre  produced  by  the  unirrigated  portion,  though 
the  amount  of  water  used  was  only  about  three  inches,  or  just  enough 
to  make  up  for  the  shortage  in  rainfall  of  the  year. 

Young  vs.  Old  Vines. — The  immunity  of  young  vines,  and  of  old  vines 
which  had  been  grafted  about  1897,  is  explicable  on  the  theory  that  they 
were  enabled  to  withstand  the  drought  because  they  did  not  bear  in  1897 
and  were  thus  saved  the  drain  of  that  heavy  crop.  The  same  reason  may 
account  to  some  extent  for  the  immunity  of  certain  light-bearing  varieties. 
That  vines  on  other  soils  and  in  other  localities  have  escaped  the  destruc- 
tion that  has  overtaken  the  West-side  vineyards  is  due  doubtless  to  the 
fact  that  the  three  destructive  factors  of  drought,  heavy  bearing,  and 
leachy  soil  have  not  elsewhere  been  so  great  nor  simultaneous. 

Not  Anaheim  Disease. — The  reasons  which  have  led  us  to  reject  as 
unproven  the  theory  which  ascribes  the  death  of  the  vines  to  the  Anaheim 
disease  are  based  upon  the  divergence  of  the  symptoms  from  those  which 
distinguish  that  disease  as  characterized  in  Bulletin  2  of  the  Division  of 
Vegetable  Pathology  of  the  U.  S.  Department  of  Agriculture,  entitled 
"  The  California  Vine  Disease/'  by  Newton  B.  Pierce.  This  pamphlet 
must  be  considered  as  the  highest  authority  on  this  disease,  as  it  is 
almost  the  only,  or  at  least  the  most  complete  and  voluminous,  publi- 
cation on  the  subject. 


—  10  — 


Characteristics  of  Anaheim 
Disease. 


Characteristics  Shown  by  Dying  Vines 
in  Santa  Clara  Valley. 


Mission  more  susceptible  than  Mataro 
or  Zinfandel. 

Vines  in   shade  of  trees  less   rapidly 
affected. 

Grafting  the  vines  does  not  save  them. 


Cuttings  from  affected  vines  which 
show  the  disease  die  as  soon  as  the 
parent  vines. 


Rotting    of    the    roots    is    a    constant 
symptom. 


:Page 
141 


Mataro  and  Zinfandel  have  died  more 
generally  than  the  Mission. 


Vines  near  trees  have  suffered  as  much 
108  or  more  than  others. 


138 


152 


52 


All  the  recently  grafted  vineyards  are 
healthy. 

There  are  many  instances  in  which  cut- 
tings taken  during  the  last  two,  three, 
and  four  years  from  Mataro  and  Mis- 
sion vines  which  are  now  dead  have 
been  planted,  or  grafted  on  phyllox- 
era-resistant stock,  and  have  now 
resulted  in  vigorous,  healthy  vines. 

Roots  of  most  of  the  injured  vines  are 
sound. 


*The  numbers  refer  to  pages  in  the  above-mentioned  bulletin. 

To  these  contrasts  should  be  added  the  apparent  recovery  of  Grenache 
vines,  which  were  badly  affected  last  year  and  this  spring,  but  which  in 
August  were  making  a  vigorous  healthy  growth.  Though  Mr.  Pierce 
may  not  make  the  statement  definitely,  the  impression  left,  on  reading 
his  publications  on  the  Anaheim  disease,  is  that  it  is  cumulative  and 
progressive  and  that  the  attacked  vines  never  recover. 

These  contrasts  prove  either  that  the  Anaheim  disease  is  not  the 
cause  of  the  death  of  the  Santa  Clara  vines,  or  that  the  characteri- 
zation of  the  disease  as  given  in  the  publication  above  referred  to  must 
be  profoundly  modified  to  include  the  symptoms  exhibited  by  these 
vines.  There  is,  however,  no  reason  at  present  to  suggest  the  Anaheim 
disease  if,  as  seems  at  least  very  probable,  the  causes  here  outlined  are 
sufficient  to  account  for  the  observed  effects. 


Practical  Lessons. — This  serious  disaster  contains  two  important  prac- 
tical lessons  to  horticulturists,  and  especially  to  vineyardists:  First, 
the  necessity  of  having  on  hand  the  means  for  supplementing  a  deficient 
rainfall,  even  in  what  are  usually  considered  the  non-irrigating  districts; 
and  second,  the  importance  of  choosing  varieties  adapted  to  special 
locations,  soils,  and  climates.  This  question  of  adaptation  is  particu- 
larly important  to  grape-growers  who  are  planting  phylloxera-resistant 
stock,  as  all  the  good  and  thoroughly  resistant  vines  are  comparatively 
limited  in  their  range  of  adaptability.  Wherever  new  vines  are  planted 
in  the  devastated  area  it  would  be  extremely  unwise  to  plant  any 
variety  which  has  not  well-proved  drought-resisting  qualities.  The 
resistant  vines  which  have  shown  the  best  results  so  far  on  the  west  side 
of  the  Santa  Clara  Valley  are  Rupestris  St.  George,  Rupestris  Martin, 
and  Champini.     The  last  has  thriven  almost  or  quite  as  well  as  the  two 


—  11  — 

Rupestris  varieties,  but  unless  it  shows  marked  superiority  in  some 
other  way  the  others  are  to  be  preferred  on  account  of  their  superior 
phylloxera-resistant  qualities  and  the  greater  ease  with  which  they 
root.  The  suggestion  that  Rupestris  St.  George  is  resistant  to  the 
Anaheim  disease  is  certainly  premature  when  based  upon  its  behavior 
in  the  Santa  Clara  Valley,  in  view  of  the  fact  that  the  presence  of  that 
disease  in  the  valley  is  more  than  doubtful,  for  even  Mr.  Pierce,  the 
acknowledged  authority  on  this  disease,  after  making  an  examination 
of  the  afflicted  vineyards,  says  in  the  "California  Fruit-Grower"  of 
July  27,  1901,  that  he  "will  not  express  an  opinion  at  this  time  as  to 
the  presence  or  absence  of  the  California  (Anaheim)  vine  disease  in  this 
district." 

FREDERIC  T.  BIOLETTI. 

E.  H.  TWIGHT. 


